XXXIX 



CLASSES, DIVISIONS, AND ORDERS 



OF 



BRITISH PLANTS. 



Class I. DICOTYLEDONES \ 



Stems when perennial composed of bark, wood, and pith. 

 The wood furnished with medullary rays and increasing by the 

 addition of concentric layers externally. Leaves usually net- 

 veined. Cotyledons 2 or more, opposite or whorled. Each 

 floral whorl composed of 5 or 4 parts. 



Division 1. THALAMIFLOR^E. Pet. distinct (rarely 0) and 

 as well as the stam. growing" separately from the 

 sepals, hypogynous page 3 



Division 2. OALYCIFLOR^E. Pet. distinct and, as well as 



the stam., perigynous or epigynous 82 



Division 3. COROLLIFLOR^E. Pet. united, at least at the 



base. Stain, mostly epipetalous 182 



Division 4. MONOCHLAMYDE^S. Only a single perianth 



or none ; . . 349 



Division 5. GYMNOSPERMJE. Ovules and seeds apparently 



naked. Ovary and styles wanting. Perianth wanting. 390 



Division 1. THALAMIFLOR^E. 



* Apocarpous. 



1. Hanunculace.ee. Stam. polyandrous (rarely pent- 

 androus). Pistils usually many, of achenes or follicles. 

 Rarely (in Actcea] a many-seeded berrylike carpel 1 



2. Berberidacece. Stam. 6 or 4, opposite the petals ; 

 anth. opening by valves from the bottom 1C 



1 The characters are drawn to suit our plants. 



